JPH0250562A - Busy detecting system for telemeter system - Google Patents

Abstract

PURPOSE:To delete the current necessary for the line checking signal sending by discriminating the resending emergency degree of an electric signal to be resent with the discriminating means of terminal equipment when a center is busy, sending intermittently a line checking signal at a time interval in accordance with the resending emergency degree, detecting the idle condition of a line and resending an electric signal to a center. CONSTITUTION:Terminal equipment is provided with a discriminating means, a line checking means and a resending means and when the discriminating means, when the self-call encounters during the busy of the center, discriminates the resending emergency degree of an electric signal D to display the use quantity and the security information of the gas, etc., to be resent. Then, the line checking means sends intermittently a line checking signal C at the time interval in accordance with the resending emergency degree and detects the idle condition of the line. When the line checking means detects that the line is in the idle condition, the resending means sends an electric signal to the line. Thus, the line checking signal is sent intermittently at the suitable time interval during the offhook of the center. Thus, at the time of resending, the current consumption can be drastically reduced.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention transmits electrical signals from terminal equipment such as a plurality of meter reading meters and monitoring sensors to a center such as a meter reading center or a monitoring center via a general subscriber line. This invention relates to a busy detection method for a transmitting telemeter system.

<Prior art> In general, a telemeter system connects multiple terminal devices such as meter reading meters that detect usage of water, gas, electricity, etc. and monitoring sensors that collect security 4 blueprints, and a computer at a center to a general subscriber line. The terminal equipment that receives control signals from the center performs measurement (integration, photography/recording, storage, conversion into electrical signals, transmission control, etc.) and sends the data to the line, while also receiving this data. The computer at the center calculates charges, performs statistical processing, and controls terminals. And with the recent rise in labor costs for meter reading and monitoring, research into this telemeter system is underway.

Development is actively underway, and some are being put into practical use.

Furthermore, the telemeter system is characterized in that many terminal devices with low traffic are scattered on the line.

Now, in the above-mentioned telemeter system, when a call from a terminal device encounters a call while the center is busy, it is necessary to retransmit the data. Conventionally, this data retransmission was performed using the method shown in Figure 4. There is. For comparison, when the center is on-hook, as shown in Fig. 3, a pulse-like call request signal S is first sent from the terminal equipment to the general subscriber line, and then it is detected whether or not the center is on-hook. The line check signal C7><is sent for J seconds and after confirming on-hook, the data signal (■) is immediately transmitted. On the other hand, if the center is off-hook for r seconds as shown in FIG. The line check signal C continues to be sent, and the sending stops 5 seconds after the center goes on-hook, and after confirming on-hook, a data signal is transmitted.This data retransmission method is used for security purposes where the data content requires emergency retransmission. This is the same regardless of whether it is data or general meter reading data.

<Problems to be Solved by the Invention> However, in the conventional telemeter system described above, when the center is off-hook, the terminal equipment continues to send the line check signal C during the off-hook period (approximately 14 seconds), so it can be retransmitted at the time of on-hook. On the other hand, it has the advantage of
There is a drawback that the current for the line check signal C continues to be consumed. If there are connection requests from many terminal devices on the line at the same time and the off-hook period is long, the benefit of being able to quickly retransmit is outweighed by the consumption.
The disadvantage of increased I flow is a bigger problem.

Therefore, an object of the present invention is to reduce the current consumption during retransmission while suppressing the transmission delay to a short time by transmitting the line check signal intermittently at intervals according to the importance of the data content to be transmitted. It is an object of the present invention to provide a busy detection method for a telemeter system that can significantly reduce the amount of noise.

<Means for Solving the Problems> In order to achieve the above object, the busy detection method of the telemeter system of the present invention provides a method for detecting a busy state in a telemeter system in which a plurality of terminal devices and a center are connected by a general subscriber line. determining means for determining the retransmission urgency of the content of the electrical signal to be retransmitted when a call encounters a busy center;
A line check means detects whether the line is idle by intermittently sending a line check signal at time intervals according to the retransmission urgency determined by the discrimination means, and the line check means detects when the line is idle. The present invention is characterized in that the terminal device is provided with retransmission means for retransmitting the electrical signal when detected, thereby reducing the current required for retransmission.

<Function> The terminal device is equipped with a discriminating means, a line checking means, and a retransmission means, and the discriminating means indicates the amount of gas used and security information to be retransmitted when its own call encounters a busy call at the center. Determine the urgency of retransmission of the electrical signal. Then, the line check means detects the idle state of the line by intermittently sending out a line check signal at time intervals corresponding to the retransmission urgency. Then, when the line check means detects that the line is idle, the retransmission means sends the electrical signal to the line. In this way, the line check signal is sent intermittently at appropriate time intervals while the center is off-hook, so the current consumption during retransmission is significantly reduced compared to the conventional system where the line check signal was sent continuously. Reduced.

<Example> Hereinafter, the present invention will be explained in detail with reference to illustrated embodiments.

A terminal device such as a meter reading meter or a monitoring sensor of a telemeter system (not shown) has a determining means, a line checking means, and a separate sending means. The above-mentioned determination means checks whether the content of the data to be retransmitted is security data or not, and determines the retransmission urgency when a call from the terminal equipment via the general subscriber line encounters the other party's center being busy. Divide into 2 ranks. The line check means sets the transmission interval of the line check signal C (see FIGS. 1 and 2) to 1.0 or more depending on the retransmission urgency rank determined by the determination means. Seconds, I! The line check signal C is set to one of seconds, and a line check signal C that lasts for 5 seconds at this time interval and detects the idle state of the line is sent to the general subscriber line. These determining means and line checking means are specifically constructed of electronic circuits such as microprocessors. On the other hand, the retransmission means has a known configuration, and when the line check means detects that the line is idle, it retransmits the data to the Senota via the general subscriber line.

A busy detection method for a telemeter system using the terminal device having the above configuration will be described below with reference to FIGS. 1 and 2.

First, when the center is in an on-hook state, as shown in FIG. 1, which is the same as FIG.
After sending out the line check signal C which lasts for 5 seconds, the idle state of the line is detected, and then data signals such as security data and other meter reading data are transmitted to the center.

Next, as shown in FIG.
A line check signal C that lasts for 2 seconds is sent intermittently at short time intervals of 13 seconds, and after the center goes on-hook after 11 seconds, the idle state of the line is detected by the first line check signal C, and then the security data D is sent. Transmit it to the center. On the other hand, when the data signal to be transmitted is meter reading data, etc., after sending the transmission request signal S, a line check signal C lasting 5 seconds is sent intermittently at a long time interval of 13 seconds, and the center sends it for 14 seconds. After turning on-footer, the first line check signal C detects that the line is free.
Next, meter reading data etc. are transmitted to the center.

In this way, in the above embodiment, when the center is off-footer, the line check signal C is not sent out continuously as in the conventional example shown in FIG. Since the system detects the idle state of the line by intermittently transmitting data at time intervals (1,,I,) according to the (2 ranks), the transmission delay can be kept as short as possible according to the importance of the data signal. This has the advantage of significantly reducing the current consumption required to send line check signals while keeping the current consumption low, as well as downsizing the power supply circuit (batteries, transformers, etc.) for supplying current and making it possible to perform multi-jobs at intervals.

As a comparative example of current consumption, for example, the duration J of the line check signal is 1 ms, the current required for this is 5 mA, the time interval r is 3 x 60 s, Iy is 10 x 60 s, and the second
As shown in the figure, if the busy line is canceled and connection is established at the third line check, the amount of current consumption will be as follows.

For security data = 4.17x 10-'mAs For other data: 1.25XlO-5mAs On the other hand, for the conventional example shown in Figure 4, 5mAX (5X 60s + IO-3s) = 150
Therefore, according to this embodiment, the current required in the conventional case of 1500 mAs can be significantly reduced to about 40 nAs.

In addition, in the above embodiment, the case where the data retransmission urgency is divided into two ranks is described, or this is divided into three ranks as necessary.
It can also be divided into ranks or higher.

Furthermore, it goes without saying that the present invention is not limited to the illustrated embodiment.

<Effects of the Invention> As is clear from the above explanation, the busy detection method of the telemeter system of the present invention is applicable to a telemeter system in which a plurality of terminal devices and a center are connected via a general subscriber line. When a call is encountered, the determination means of the terminal equipment determines the retransmission urgency of the electrical signal to be retransmitted,
The line checking means intermittently sends out a line check signal at time intervals according to the retransmission urgency as a result of this determination, detecting the line's idle state, and when it is detected that the line is about to become idle. Since the electrical signal is retransmitted toward the center by the retransmission means,
Compared to conventional systems that send line check signals continuously, the current required to send line check signals can be significantly reduced, and the power supply circuit for supplying current can be made smaller and multi-jobs can be performed at intervals. Become.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining an example of the busy detection method of the telemetry stem of the present invention, and FIGS. 3 and 4 are diagrams for explaining the conventional busy detection method. C... Line check signal, D... Data signal, H.
...Center busy time, 1, It...Line check signal interval, J
・Connection time of line check signal.

Claims (1)

[Claims] (1) Electrical signals from terminal devices such as multiple meter reading meters and monitoring sensors that detect usage of water, gas, electricity, etc. and collect security information are sent to meter reading centers, monitoring centers, etc. via general subscriber lines. In a telemeter system that transmits to a center, when a call from the terminal equipment encounters a busy center, a determining means for determining the retransmission urgency of the content of the electrical signal to be retransmitted, and a determination result of the determining means. A line check means detects whether the line is idle by intermittently sending a line check signal at time intervals according to the retransmission urgency; and when the line check means detects that the line is idle, the electric signal A busy detection method for a telemeter system, characterized in that the terminal device is provided with a retransmission means for retransmitting a message, thereby reducing the current required for retransmission.